Determine the equation of the given conic in xy-coordinates when the coordinate axes are rotated through the indicated angle.
xy = x + y, ϕ = π/4

Which equation can be simplified to find the inverse of y = 2x2?

65 8 7 4 5 6 8 4 3 2 1 9 5 6 4 2 1 6 5 1 5 1 3 2 3 5 multiply the third number in the first row by the seventh number in the third row. add this result to the fifth number in the second row. add to this total ten times the fourth number in the third row. subtract the eighth number in the first row from the result.

The base of a triangle exceeds the height by 9 inches. if the area is 180 square inches, find the length of the base and the height of the triangle.